Drill



Sept. 27, 1938. J. H. LIND 2,131,056

DRILL Filed March 25, 1936 INVENTOR J0]!!! J7 Zind BY I Patented Sept. 27, 1938 2,131,056

UNITED STATES PATENT OFFICE John Herman Lind, Santa Barbara, Mexico, as-

signor to American Smelting and Refining Company, New York, N. Y., a corporation of New Jersey Application March 25, 1936, Serial No. 70,747

4 Claims. (01. 255-64) This invention relates to drills such asare In providing the slit I! for the end of the drill ordinarily employed in rock drilling operations rod to permit expansion of the end of the rod and more particularly to certain improvements in when pressure is applied to the spreader or plug detachable drill bits. II, it is highly desirable to drill the end of the I Among other features, the invention provides drill rod at the furthest extremity of the slot 5 a detachable, two-piece drill bit in which a minias shown in the drawing to prevent cracking or mum of material is utilized in the cutting edge splitting of the rod in use. While only one type proper thus effecting a material saving in those of cutting edge has been shown in the drawing, operations that contemplate discarding dulled it will of course be obvious to those skilled in bits. The invention also provides a novel means the art that any desired type of cutting edge IQ. for frictionally securing the detachable drill bit such as a four-comered or rosette bit may be to the drill rod. used.

The invention also consists in certain new and It will also be apparent that the present inoriginal features of construction and combination vention provides a drill in which the amount of 5 of parts hereinafter set forth and claimed. material used in the cutting edge proper is at In the accompanying drawing there is shown a minimum. All other parts 01' the assembly can,

- for purposes or illustration one form of a device of course, be reused and, therefore, it is only necembodying the invention, in which essary to change the cutting edge when same be- Fig. l is a view partly in section showing the comes dull, assembled drill rod and bit; What is claimed is: 20

Fig. 2 is a view taken at right angles to the 1. The combination with a drill rod having an assembly shown in Fig, 1; internally tapered end, of a recessed cutting por- Fig. 3 is a cross section taken along the line tion interlockingacollar portiomsaid cutting and 0f E- and collar portions being irictionally secured to said Fig. 4 is a view in perspective of the dismantled 'drill rod by a tapered. plug, the head of said D 8 25 device. engaging the recess of the'cutting portion and Like reference characters denote like parts the taperedportion of said plug engaging the in the several figures of the drawing. internally tapered end of said drill rod.

Referring mere particularly to the drawing, l0 2. The combination with a drill rod and a twois a hollow drill rod having internally and exterpiece bit consisting of a'body portion and a de- 30 nally tapered end II; the latter being provided tachable cutting edge portion, of an additional, with slit l2. The bit consists of a body portion single member separate from said rod and bit or collar l3 having a slot l4 and a cutting edge locking the cutting edge in the body portion portion I! provided with recess Hi. There is also or said .bit and frictionally securing said body provided a tapered plug or wedge l1 having portion to said drill rod. 35 head 3. The combination with a drill rod, of a bit To assemble the drill. the cutting edge porcomprising a collar and a detachable cutting edge tion I5 is caused to engage the slot ll of the portion interlocking said collar, and a wedge collar l3 and is locked therein by insertion of member telescoping the end of said drill rod and 40 the head i8 of plug l'l in the recess I6. The frictionally engaging said collar on said rod. 40 plug I1 is then inserted in the tapered: end of the 4. The combination with a drill rod having a drill rod whereby pressure applied to the cutting hollow, tapered end, said end having slits therein, edge tends to spread the tapered end ll of the of a. detachable collar, a recessed cutting edge drill rod thus frictionally engaging the collar l3. portion engaging said collar, and a tapered plug 7 To dismantle the bit it is only necessary to give for irictionally securing said collar-to said rod, 45

the collar 8. light sharp blow which causes the said tapered plug having a head engaging the retapered plug lltg slip thus releasing the collar cess in said cutting edge portion. and cutting edge from the end of the drill rod. JOHN HERMAN 

